Engine - Hesitation or Surge at 55 to 60 MPH
No.: TSB-97-15-001DATE: March, 1997
MODEL: See Below
SUBJECT:
HESITATION AND/OR SURGE AT HIGHER SPEEDS (4G64 2.4L SOHC ENGINE)
PURPOSE
This bulletin contains repair procedures for an engine hesitation or surge which can occur at higher speeds (55 to 65 mph) on affected vehicles (1996-97 Galant and 1996-97 Eclipse Spyder GS) equipped with the 4G64 2.4L SOHC engine.
SYMPTOM AND CAUSE
Customers may report a surge or hesitation when driving at sustained speeds above 55 mph. Diagnosis may point to a malfunctioning air flow sensor (AFS), however, the problem may still occur after installing a new AFS. This symptom may be caused by misalignment of the throttle body on the intake manifold. A gap caused by this misalignment can create supersonic noise (or turbulence) which causes the AFS to operate improperly.
REMEDY
If you encounter a complaint of high speed hesitation and duplicate the condition, proceed with the following repair procedures to properly align the throttle body and intake manifold. Install a new throttle body gasket when doing this repair.
AFFECTED VEHICLES
1996-97 Eclipse Spyder GS 2.4L
1996-97 Galant
REPAIR PROCEDURES
Refer to section 13A in Galant Service Manual, Volume 1, for more detailed information about throttle body removal.
1. Loosen and remove the throttle body mounting bolts, then remove the throttle body from the intake manifold.
Note:
Do not remove the water hoses and harness which are connected to the throttle body.
2. Remove the throttle body gasket.
3. Clean the throttle body and intake manifold mating surfaces thoroughly.
4. Install the new throttle body gasket.
5. Install and temporarily finger-tighten the throttle body bolts.
6. For proper throttle body to intake manifold alignment, lift and move the throttle body into the proper position to eliminate the incorrect gap shown in the illustration. While holding the throttle body in the aligned position, tighten the throttle body bolts to l9 Nm (14 ft-lbs).
7. Test drive the vehicle to make sure the hesitation and/or surging is eliminated before returning the vehicle to the customer.
PARTS INFORMATION
Part Number Description
MD184046 Throttle Body Gasket
WARRANTY INFORMATION
Throttle Body Gasket Replacement
Nature Code: 05M Cause Code: 450
Labor Operation No.13312110 Time Allowance: 0.6 hr.
Warranty Coverage: Emissions - 5 years/50,000 miles.
Special Warranty Information: Normal warranty procedures apply.